Method of expanding metal



Patented Apr. 28, 1931 y HARVEY IVI. GERSMAT, GF BUFFALO, NEUYOREI RIETI-10D OF EXPANDING METAL ,Application led lApril 30, 1925. Serial No. 105,722.

This invention relates to a method of eX- panding metal and proposes a method by which the expanded article has the same length as the blank from which itis produced and the expansion is effected in connection with the elongation of the strands and bonds. The invention is generically applicable to the production of expanded metal articles of different kinds and for different uses in structural operations, and is herein claimed in its generic aspect and also in one specific aspect, namely, tne production of expanded metal beams or Vload bearing members.

The principal objects 4of the invention are to enable the production of expanded metal articles in forms Which are highly advantageous by reason of their structural features and physical characteristics and quali- 30 ties and which cannot be satisfactorily produced by methods heretofore employed or proposed, and to provide a method Which, along with these advantages, may be carried v out in connection with standard rolling 2D practice as utilized for the production of the blank, which may be practiced at relatively loW cost, formable to the peculiar conditions under which the work is done, that is toV say, the 30 rapid travel of the blank and its rapid cooling. The invention is practiced in connection with a heated rolled blank and the method is completed before the blank has cooled to a degree suflicient to interfere With the Working of the metal. Preferably the invention is practiced continuously with the delivery of the blank from a standard mill pass and the method is commenced With the blank at or near the degree of heat which it has at the delivery stage of the rolling operation.

According to the invention theY heated blank is first suitably slitted and its eXpansion is then effected by rollingv a portion Vof the bla nk in which the slits are incorporated, the rolled portion being thereby reduced in thickness and increased in length, and during the elongation of the rolled portion which occurs after and results from the rolling operation simultaneously and progresand which is especially consively increasing they width of the blank between lunelongated portions at each side of the rolled portion, thereby simultaneously to compensateand continuously take up the elongation of the rolled portion at a rate corresponding to that of the elongation and with resultant expansion of the blank. The increase in the Width of the blank between the unelongated portions may be effected in different Ways. As shown it is effected by spreading or fanning out the unelongated portions. The'method is thus one in Which no Tvarping or buckling of the metal lis produced or permitted and in which there arey L no factors by Which inequalities in form or physical characteristics are introduced or by which, as compared Withv cold expanding operations, anyinternal stresses arevdeveloped. It follows that the product is one in which the elongated strands and bonds are uniform in thickness,'dimensions andy physical qualities and may lie in planes coincident With the mean or general plane of the expanded article. f Y

As applied to load bearing members the Web is slitted and by the subsequent rolling elongated While the flanges remain ofthe same length as in the blank and during the elongation of the Web are simultaneously and progressively and at a rate proportionate to the elongation spread or fanned out so as to compensateor take up the elongation as it Voccurs and with resultant expansion of the blank into the load bearing member Which is desired, although this -is not necessary, may be passed through finishing rolls. v i

kThe above and other characterizing yfea- Cir tures of the method Will be set forth as the description proceeds and yWill appear from the accompanying drawing which illustrates apparatus by Which the method may vbe practiced, the steps in the evolution of the blank into the completed product, and a portion of an expanded beam produced by the method.

In said drawing: Figure l is a plan View of the apparatus, showing -the blank in its different stages of treatment.V

Uitl

.panelpoints of the truss.

l1 igure 2 is a longitudinal sectional View of the same.

Figure 3 is a fragmentary perspective view of one of the rolls which reduce and elongate the slitted portion of the blank.

Figure el is a plan view of a portion of the cxpa ded beam.

Figure 5 is a section on theline 5`5 of lfigure 4.

"he method is preferably practiced continuously and in connection with the rolling of the blank. In such case the heat of blank as it comes from the stand of the mill by which its developmenthas been brought to the stage desired is utilized and the method is completed with final determination of the form and physical qualities ofthe expanded article while the-blank is yet sutiicicntly hot for its parts to be worked and relocated.

.'lhe method is applicable to different forms of beams and other expanded arti cles and is herein illustrated in connection with the production of a beam in the form of a simple latticetruss whereinfthe struts have a single line of intermediate bonds representing points of intersection, the remaining bondsbeing the connections between the struts and the chords, that is to say, lthe The blank for such a beam will haveparallel slits arranged .in three longitudinal rows ywith the slits of each row in alinement and-staggeredrelatively to the slits of the adjacent row vor rows, the relative length and arrangement of the slits being such asto yprovide for the symmetrical relation of the .bondsfa-nd the struts by making due allowance for the elongation of the bonds in the vexpanded product.

The blank B-is shown fas .havingvaf cross section similar to that ofpa standardI- beanr .and is providedwith parallel-flanges l and a web2. The blank maybe delivered from a Astandard mill pass (not shown) `-and -is first acted upon by slitting-.rolls 3 which slit `the web. Theserolls .maybe of any suitable construction andl are merely shown diagrammatically.

The web having'thus Abeen slitted in any usual or suitable manner, theblank-is now ready for reduction and expansion. These operations may be .performed-in one stage orin'more than one stage according tothe degree of reduction and expansion desired, it beingpractical to continue the .expansion to a point where the struts assoc-iated'wfith each chord extend at approximate-angles of G0 degrees to one another. Two stages of Vreduction. and expansion 4are'shown in the drawing.

From the slitting rollstheblankipasses to reducing rolls llfwhich act Aonthe slitte-d' portion `of the web and:reduce'itsfili-ickness with censequent elongation. The slittedpertien of the web which has been acted on by the reducingrolls will, owing to the elongation, travel at a greater rate than that of the blank as it passes through the slitting rolls, the increase in speed being proportionate to the percentage of reduction. For example, if the speed ofthe blank up to the reducing rolls be 100 feetper minute the speed of the web` upon passing from the reducing rolls may be approXimatelyVlQO feet per minute. For practical reasons-the reduction in any onepair of rolls is limited to substantially twenty-live percent and where greater reduc- -tion is rrequired additional rolls are necessary. The reducing rolls'arc employed in cooperation with -means for increasing the `width ofthe blank simultaneously and con- Vti-nuously with the resultant elongation :and .at a rate proportionate to that of the elongation.- 'fIn the embodiment disclosed such moans is constituted byshoes fwhich'fact on `the flan-ges. These shoesare preferably provitletl'innpper yand lowerpairs, one pair bein-g` ass-eciatedwith eachreducing roll and the `shces of! each pairhaving forwardlyA tivergent .guide faces 6- which bear against the innerfaces of the flanges l, the inclination -of'the'fa'ees being determined invaccordance with the requirements previously' fstatedsthatisto say, to effect the spreading ernfanning out of the-flanges -so as-to continuously compensate orv take up the elongation simultaneously? andr at a rate proportion4 .ate Vtoits progresswith resultant formation of the' reducedfand elongated part of the web vinto.open-work. The shoes 5 preferably engagethe-flanges substantially at or slightly lahead ofthe centerline of the rolls whereby they commence to act on the' ilanges substantiallyV at :the time "when 'reducing pressure is applied to the slitte'd` portions of the blank. Undeisuclis pressure there is aA tendency for ltheparts towiden very slightly and the ini- 'tial 'action of the shoes' is, therefore, to prevent iany Jwelding or freezing ofthe reduced portions along the sides of the slits {prior y'to expansion and vthereby to insure that during'eXpansion no stresses are imposed on the panel point bond providing poi tions such as might arise if it were necessary vtov separate any adjacent st 'ands which had become partially welded.

It will be noted that the spreading or fanvning out ofthe flanges is not resorted to for the. purpose of elongating the struts and has noeffect on the length .of the struts but is resortedl to-for the purpose of compensating or taking up the elongation of the struts as it progresses, and-accomplishes this `result.

byfcausing the strutsA tov-have a' lateral travel ordeflectionwhichV with respect to the length of thebeam equalizes their elongation. The

-formation -of theuolled" portion 'off the web into VAopenAi work 1 is`A thus accomplished simullaneously and at a proportionate rate to the elongation of the struts and the bonds.

Any tendency for the struts in consequence el their elongation to shear or partially .shear from the adjacent chord portions may he couuteractcd in various Ways. As herein shown this is accomplished by forming the reducing rolls whereby they will not act on the bonds which connectthe struts and chord portions. Thus the reducing rolls are Jtermed adjacent their margins with recesses or flats 7 ot suitable outline7 preferably triangular outline and Which are arranged at such intervals as to coincide with the panel point bond portions of the blank. rllhe result of the provision of the recesses or flats 7 is that the said panel point bond portions are not rolled and hence are not reduced and elongated but remain of their original thickne. It follows that substantially triangular leentorced panel points are provided and that the redaction and elongation ot the struts are confined to rectangular areas which said panel points adjoin. lf a second stage of expansion be required, as is assumed by the drawing, this is eitected by reducing rolls 8 and shoes 9 Which are duplicates in structure and arrangement of the rolls 4l and shoes 5. The rolls 8 act on the web as it passes from the shoes and carry the reduction and elongation to a further degree and the shoes 9 act on the flanges 2 in the same manner as the shoes 5 and carry the expansion to a corresponding further degree.

Having fully described my invention, claim:

l. The method of expanding metal which is practiced With a heated slitted blank and which consists in reducing and thereby elongating a part of said blank in which slits are incorporated Without elongating adjacent pares and increasing the Width ot' the blank at the beginning and during the progress of the elongation and at a proportionate rate, thereby continuously to compensate and take up the elongation at a rate proportionate to its progress.

2. The method of expanding metal Which is practiced With a heated slitted blank and `-Which consists in reducing and thereby i' the slitted portion and at the beginning and during the progress ot such elongation' aot-A during the progress of such elongation andA at a proportionate rate spreading or fanning out the unslitted portions, thereby continuously to compensate and take up the elongation as it progresses.

5. The method ot expanding metal which is practiced with a heated blankhaving a slitted portion and whichv consists in reducing and thereby elongating the slitted portion and at the beginning and during the progress ot the elongation and at a proportionate rate spreading or tanning out the unelongated portions at each side of the slitted portion, thereby continuously to compensate and take up the elongation as it progresses.

6. The method of expanding metalwhich is practiced with a 'heated slitted blank and which consists in reducing and thereby elongating a part ot said blank in which slits are incorporated Without elongating adjacent parts and causing a lateral travel or deflection of the reduced parts at the beginning and during the progress of their elongation and at a proportionate rate by Which such elongation is equalized With respect to the length of the blank.

7. The method ot making an expanded load bearing member from a heated flanged rolled blank Which consists in slitting the web of the blank, rolling the slitted Web to reduce and elongate it Without altering the length of the flanges, and acting on the flanges at the beginning and during the progress of the elongation of the rolled Web and at a proportionate rate whereby to increase the Width of the blank, and to compensate and take up the elongation as it progresses.

' 8. The method of making an expanded load bearing member from a heated flanged rolled blank which consists in slitting the web of the blank, rolling the slitted Web to reduce and elongate it Without altering the length of the flanges and spreading or fanning out the flanges at the beginning and during the progress of the elongation ot the rolled Web and at a proportionate rate whereby to increase the Width of the blank and to compensate and take up the elongation as it progresses.

9. The method of making an expanded load bearing memberfrom a heated flanged rolled blank which consists in slitting the web of the blank in parallel rows to provide for struts and panel points in the iinished beam, rolling the slitted web to reduce and elongate it without altering the length of the flanges and in a manner to counteract any shearing tendency at the panel points in consequence of the elongation, and acting on the flanges at the beginning and during the progress of the elongation of the rolled web and at a proportionate rate whereby to increase the width of the blank and to compensate and take up the elongation as it progresses.

Vl0. The method of making an expanded load bearing member from a heated flanged rolled blank which consists in slitting the web ol the blank in parallel rows to provide for struts and panel points in the linished beam, rolling the slitted web to reduce and elongate it without rolling the panel points and without altering the length of the langes, and actingvon the flanges at the beginning and during the progress of the elongation of the rolled web and at a proportionate rate whereby to increase the width of the blank and to compensate and take up the elongation as it progresses.

ll. The method of expanding metal which is practiced with a heated blank and which consists in rolling a slitted portion of said blank between parallel non-slitted portions thereof thereby to elongate the slitted portion relatively to the unslitted portions and commencing at the center of the roll pass and continuing throughout the elongation of the slitted portion gradually increasing the relative spacing of the non-slitted portions to counteract buckling of the rolled portion during its elongation and at the same time bring the rolled portion into flat expanded condition.

In testimony whereof l.'l aHiX. my signature.

HARVEY M. GERSMAN. 

